I actually love Carwin's fighting, it's not the most technical, it's not the most fluid, it's not the quickest... he's just a really tough, powerful fighter and you will know about it some point in the fight.
Carwin is the big bad dinosaur of the division and is huge trouble to anyone besides JDS and Cain, so despite him probably never going to hold the belt, this is very sad news.
If Carwin was in Pride, we'd probably be talking about him as one of the best HW's ever. The Brock fight was unfortunate, JDS is the only man to take it to Carwin without getting smashed up. I hope to see him fight again.